Aluminium silicon alloy with a phosphorus content of 0.001 to 0.1%



Patented Dec. 26, 1933 UNITE STATES PATENT ALUMINIUM SILICON ALLOY WITHA PHOS- PHORUS CONTENT OF 0.001 T0 0.1%

No Drawing. Application August 2, 1933, Serial No. 683,407, and inGermany August 8, 1932 3Claims.

This invention relates to aluminium-siliconalloys with a phosphoruscontent of 0.001 to 0.1%. The invention relates further to a specialmethod for the introduction of the phosphorus and also 5 the productionof pistons, bearings and other machine parts which are exposed tofrictional stressing when in use.

The invention is based on the circumstance that the addition ofphosphorus within the limits specified to aluminium-silicon-alloys with5 to of silicon has an extremely favorable influence on the slidingproperties and resistance to wear of such alloys.

The addition of the phosphorus to aluminium 5 alloys having as low asilicon content as from 5 to 15% improves their sliding properties to asubstantial degree, but this addition of phosphorus has a particularlyfavorable effect in the case of the hyper-eutectic alloys containingbetween 15 and 25% of silicon. Even alloys containing up to 40% ofsilicon, which were considered unusable by reason of their brittleness,can be rendered suitable for constructional purposes by the addition ofphosphorus within the limits hereinbefore set forth.

In addition to the specified quantities of silicon and phosphorus, thealloy may also contain additions known for aluminium alloys, of one ormore of the metals magnesium, nickel, chromium, manganese, cobalt orcopper, in the usual quantitles, in order to influence specialproperties of said alloys, such as hardness, mechanical strength orductility.

On account of the good sliding properties of such alloys it is possibleto make pistons, bearings and engine cylinders and other analogousmachine parts, such as mould tools and ram guides for briquette pressesand cylinder liners, which are exposed to frictional stresses,especially in 40 the warm, out of these alloys. In addition to goodsliding properties, the capability of said alloys of being pressed, isimproved, by the phosphorus addition, to such an extent as to enable itto be worked by means of presses.

In producing the machine parts, it is preferable to make an alloy ofaluminium and silicon of the desired proportions of composition, in thefirst place, and thereupon to add the requisite phosphorus, taking theloss by burning into consideration.

It is particularly advantageous and a further part of the invention, tointroduce the phosphorus in the form of phosphorus pentachloride, andnot in the elemental form, the result being that, in consequence of thedecomposition of the phosphorus pentachlorlde, the phosphorus isintroduced into the melt in a gradual manner and almost without anyloss. Moreover, a refining action is obtained, at the same time, throughthe liberated chlorine. For example, excellent results have beenobtained with an amount of phosphorus pentachloride corresponding toabout 0,2% of the weight of metal to be refined.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is:--

1. Aluminium-silicon alloys containing 0.001 to 0.1% of phosphorus. 5 to40% of silicon and the balance principally-aluminium.

2. Aluminium-silicon alloys containing 0.001 to 0.1% of phosphorus, 15to 25% of silicon and the balance principally aluminium.

3. Articles that are exposed to frictional stress especially at elevatedtemperatures, such as pistons, bearings, engine cylinders, machine partsand parts of briquetting presses, made of aluminium-silicon.alloyscontaining- 0.001 to 0.1% of phosphorus, 5 to 40% of silicon andthe balance principally aluminium.

ROLAND swam-Rm.

